Chipotle Customer -- They Screwed Me ... With a Side of Hardware

Chipotle did NOT nail the order of one customer, who says she found a screw buried in her burrito bowl ... and almost busted a tooth.

We're told the woman visited the Chipotle location at The Grove in LA Monday night. She ordered her usual -- a chicken bowl with brown rice, salsa, guacamole and lettuce ... to go.

She says she bit into something that "felt like a rock" and when she spit everything out, she found the screw. She immediately called the restaurant, and claims she was told there was nothing they could do about it.

So, she called Chipotle's corporate office and finally got some satisfaction -- 20 free meals. She doesn't know if that includes chips and guac, but says she'll be pissed if it doesn't.

A Chipotle rep described the situation this way, "She has been taken care of. All is well."